Abstract: A pneumatic radial tire and a method for manufacturing the same, a device for forming a band of radial tire, and a method of and device for forming a belt-band-tread rubber assembly. The pneumatic tire including a belt arranged on the radially outer side or a carcass, and a band arranged on the radially outer side of the belt and composed of continuous one to several organic fiber cords wound spirally and approximately parallel to the circumferential direction of the tire. The radial tire manufacturing method including the steps of laminating the predetermined number of belt plies on a belt drum or belt ring for forming a belt, and winding one to several organic fiber cords continuously and spirally in the cicumferential direction of the belt on the outer surface of the formed belt in order to form a band.

Abstract: A pneumatic tire having a tread portion capable of reducing the running noise. The tread portion is provided with a circumferentially extending main groove and lateral grooves extending from the main groove towards one side thereof, the circumferential pitches of the lateral grooves including at least two different pitches. The width of the main groove at the groove top is substantially constant along its length, but the sectional area is changed along its length such that{S(i+1)-S(i)}/S(i)is 0.5 to 1.5 times{P(i+1)-P(i)}/P(i)wherein S(i) is the sectional area in one pitch P(i) and S(i+1) is the sectional area in the next longer pitch P(i+1).

Abstract: A pneumatic tire has a tread pattern with blocks which are divided by two circumferential grooves extending in the circumferential direction of a tire and eighty-five or more lateral grooves crossing the circumferential grooves in a tread part. In the tread pattern, the quotient S.sub.T /S of the total groove area S.sub.T which is the sum of the circumferential groove area S.sub.G and the lateral groove area Sg in a ground contact surface S when the tire is mounted on a standard rim, inflated with a normal internal pressure and loaded with a normal load, to the ground contact area S is in a range from 0.15 to 0.25, and the rate Sg/S.sub.G of the lateral groove area Sg to the circumferential groove area S.sub.G is in a range from 0.33 to 0.53.

Abstract: A pneumatic tire which comprises a carcass and a band disposed radially outside the carcass, the band made of parallel cords wound spirally around the breaker, the band comprising a plurality of circumferential portions which are at least one parallel cord portion in which the windings of the band cords are laid in parallel with the tire equator and at least one inclined cord portion in which the windings of the band cords are laid at an inclination angle of 0.3 to 5 degrees to the tire equator, and the total circumferential length of the at least one inclined cord portion being not more than 50% of the whole circumferential length of the band.

Abstract: A pneumatic radial tire includes a belt arranged on the radially outer side of a carcass, and a band arranged on the radially outer side of the belt and composed of one or more continuous organic fiber cords wound spirally and approximately parallel to the circumferential direction of the tire. A radial tire manufacturing method includes the steps of laminating a predetermined number of belt plies on a belt drum or belt ring for forming a belt, and winding one to several organic fiber cords continuously and spirally in the circumferential direction of the belt on the outer surface of the formed belt in order to form a band. A band forming device includes a device for drawing out a cord to be wound, a device for traversing a let-off device in the widthwise direction of the belt, and a device for controlling the traverse of the let-off device.